Alex noted that the below description might not be obvious to all users.
Clarify it by adding an example.

Fixes: f3047ca0 ("Documentation: Add devlink-trap documentation")
Reported-by: NAlex Kushnarov <alexanderk@mellanox.com>
Reviewed-by: NAlex Kushnarov <alexanderk@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>